Database - Topics

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09.Data Binding.

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Data Binding. Data binding ආකාර 2 කි. One-way Data Binding - component to view (DOM) or view to the component Two-way Data Binding - component to view and view to the component. One-way Data Binding in Angular Component to view (DOM) or view to component One-way data binding will bind the data from the component to the view (DOM) or from view to the component. One-way data binding is unidirectional. You can only bind the data from component to the view or from view to the component. a). From Component to View      01.   Interpolation Binding      02.   Property Binding      03.   Attribute Binding      04.   Class Binding      05.   Style Binding b). From View to Component      01.  Event binding  From Component to View     Style and Class Binding Directives – Directives are nothing but custom html element that angular provi...
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Data Normalization

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  DATA NORMALIZATION This is a technique of splitting a complex table in to simple meaningful tables. In here arrange tables, rows and relationships between tables in order to avoid data redundancy ( අතිරික්තතාව ) and to attain data integrity ( සම්පූර්ණත්වය ).Goal, 01.    To avid data redundancy (data duplicated). 02.    To attain data integrity - Data goes to inconsistence state ( ස්ථිර නෑ , අදාළ නෑ ) . 03.    To put data in to correct table. 04.    To avoid CRUD anomalies ( අක්‍රමිකතාව ). Duplicate වෙන data නවත්වන්න ඕනේ , අදාළ නැති data store වීම නවත්වන්න   ඕනේ.නියමිත table වලට පමණක් නියමිට data යවන්න ඕනේ සහ DB එක සමග කරන CRUD operation වලදී අක්‍රමිකතා ඇති වෙන්න බෑ (අනවශ්‍ය data delete වීම , අනවශ්‍ය data add වීම ,data search කරගන්න බැරිවීම වගේ ඒවා) Partial dependency It is the dependency where non key attributes are functionally depends on any part of composite key. Full dependency It is the dependency where non ke...
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